Prolonged Right Ventricular Ejection Delay in Brugada Syndrome Depends on the Type of SCN5A Variantã- Electromechanical Coupling Through Tissue Velocity Imaging as a Bridge Between Genotyping and Phenotyping.
Circ J
; 82(1): 53-61, 2017 12 25.
Article
in En
| MEDLINE
| ID: mdl-28781330
ABSTRACT
BACKGROUND:
Patients with Brugada syndrome (BrS) and a history of syncope or sustained ventricular arrhythmia have longer right ventricular ejection delays (RVEDs) than asymptomatic BrS patients. Different types ofSCN5Avariants leading to different reductions in sodium current (INa) may have different effects on conduction delay, and consequently on electromechanical coupling (i.e., RVED). Thus, we investigated the genotype-phenotype relationship by measuring RVED to establish whether BrS patients carrying more severeSCN5Avariants leading to premature protein truncation (T) and presumably 100%INareduction have a longer RVED than patients carrying missense variants (M) with different degrees ofINareduction.MethodsâandâResults:
There were 34 BrS patients (mean [±SD] age 43.3±12.9 years; 52.9% male) carrying anSCN5Avariant and 66 non-carriers in this cross-sectional study. Patients carrying aSCN5Avariant were divided into T-carriers (n=13) and M-carriers (n=21). Using tissue velocity imaging, RVED and left ventricular ejection delay (LVED) were measured as the time from QRS onset to the onset of the systolic ejection wave at the end of the isovolumetric contraction. T-carriers had longer RVEDs than M-carriers (139.3±15.1 vs. 124.8±11.9 ms, respectively; P=0.008) and non-carriers (127.7±17.3 ms, P=0.027). There were no differences in LVED among groups.CONCLUSIONS:
Using the simple, non-invasive echocardiographic parameter RVED revealed a more pronounced 'electromechanical' delay in BrS patients carrying T variants ofSCN5A.Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Ventricular Dysfunction, Right
/
Brugada Syndrome
/
NAV1.5 Voltage-Gated Sodium Channel
Type of study:
Observational_studies
/
Prevalence_studies
/
Risk_factors_studies
Limits:
Adult
/
Female
/
Humans
/
Male
/
Middle aged
Language:
En
Journal:
Circ J
Journal subject:
ANGIOLOGIA
/
CARDIOLOGIA
Year:
2017
Document type:
Article